Train control



Sept. 20, 1932. -r. w. VARLEY ET AL TRAIN CONTROL Filed Jan. 19, 1928 3 Sheets-Sheet "4 VENTORS.

A T TORNEY Sept. 20, 1932. T. w. VARLEY ET AL 1,878,735

TRAINVCONTROL' Filed Jan'. 19., v1928 3 Sheets-Sheet 2 Nuaua/ Con/ml Jn Hich 5 BY/ZWMAZWL Sept. 20, 1932. T. w. VARLEY ET AL TRAIN CONTROL 3 Sheets-Sheet 3 Filed Jan. 19, L928 INVENTORS TTORNEY Patented Sept. 20, 1932' UNITED STATES PATENT THOMAS w. VARLEY Ann WILLIAM alarm, or NEW-YORK, 1v. Y."

TRAIN CONTROL Application filed. January 19, 1928 Serial No. 247,792.

This invention relates to the. control of trains traveling along a rightof way, as for instance railway trains traveling along a rail track it being understood that by control of trains is meant either the operation of a signal whereby the train operator is caused to control his train accordingly, or the automatic control of the train without the intervention of the operator is effected.

10 Une object of the invention is to provide apparatus such that the desired objects may be obtained when the control between the vehicle and right of way is efiected through the instrumentality of thermionic vacuum tubes, the desired control being effected by change in character of the operation'of the tube or tubes.

' In carrying out our invention we preferably make use of a thermionic vacuum tube of t 1e audion type, and effect the desired control by causing a change in the character of operation of the tube by changing the oscillatory character of the tube as by changing it from oscillating to non-oscillating or from one character of oscillation to another character of oscillation such as by changing from one frequency of oscillation to another frequency of oscillation. A control between the vehicle and right of way may be thus effected vJoy means of oscillations of such high vfrequencies as to come within the class known as-radio frequencies.

This has many advantages amongwhich' may be mentioned the permissible fiexibil'ity of relative positioningfof the relatively moving parts upon the track and vehicle respectively, and the lack of necessity ofhaving the vehicle parts'run close to those on the right of way whereby danger of the relativelymoving parts coming together and being broken, and on the other hand too wide separations of 7 those parts causing failure of operation, is

avoided.

, condition of the system isto produce-adanger condition either as'to signal orautomatic control of the train so that the efi'ect of a controlling influence is necessary to maintain clear and equipmentadapted for cooperation with hicle may proceed.

A. further object of the invention is to ef fect control of a vehicle as indicated in combi nation with a speed control means. a

A further obj ect-of the inventionis to pro vide means in a system of the character as indicated whereby the operator may at will obviate .the efiect on the vehicle of automatic devices otherwise acting upon the vehicle. A further obj ect of the invention is to provide in a system of the character as indicated means for effecting control as to danger, caution .and clear'conditionsof the right of way. 1' p A further object of the invention isto provide -a system of the character as indicated whereby the desired control is effected by reason .ofthe cooperative actionof a plurality of thermionicvacuum tubes.

Other and ancillary objects of theinvention will appear hereinafter.

In theaccompanying drawings which illustrate the invention r Fig. 1 is a diagrammatic view of a vehicle equipment for'asystem of control embodying the invention; a. T

Fig. 2 is-a diagrammatic View ofv a railway track. and equipment adapted .to cooperate with the vehicle equipment of Fig. 1 so Fig. .3 is a diagrammatic view showing another 'form of vehicle and track equipment; I

Fig.4 is a diagrammatic view of another form of vehicle and track equipment;

Fig. .5 is a diagrammatic View showing another form .of vehicle equipment; and

Fig. 6 is a diagrammatic view of a track conditions or conditions under which the vethe vehicle apparatus of Fig. 5.

Fig. .7 is a view showing in side elevation the speed controlled disk and the time-con,

7 trolled disk and the manner .of cooperation.

A further object of the invention, is 0011-. sistently with the aforesaid character of control, to provide means whereby the normal of contacts thereon. I 1 -Referring to the drawings andfirst to Fig ures 1 and2, there is thereinnillustrated a system of train control wherebya vehicle or train upon a railway trackis controlled .by controlling the oscillatory character of thermionic vacuum tubes of the 'audion type.

These tubes are controlled by means of track instruments which are in turn controlled by Wayside signals or other means indicative, of

the condition of the track ahead; I

The apparatus shown in the figures referred to comprises a run-down device which is operated from the running gear of the vehicleso as to run down as the vehicle progresses. Having started to run down at the beginning of a block, if the conditions are clear in the-next block the run-down device will bei'ese't to" its initial position at appropriate times without causing any effect upon the progress of the vehicle. If, however, there are caution? conditions in the" next block the run-down device will continue its movement, and in cooperation with a speed control device so that the engineer is obliged to keep his train within the prescribed speed limits in order to avoid the application of brakes and the stopping of his train. If at the end of the caution block the conditions in'the next block ahead have become clear the speed control and rundown devices will be restored to the initial clear position so that normal conditions are resumed or, if the signal at the end of the caution block is at danger the run-down device will continue its movement and the brakes will'be applied and the vehicle stopped or, if the signal at the end of the caution block is another caution'signal, the rundowntand speed control devices will be returned to the initial caution position so that the caution conditions of operation will be continuedithrough'the second cau- The run-down device and its cooperating speed control device comprises a worm wheel or disk 1 which is driven in the direction of the arrow at by means of'a worm 2 driven by'a flexible shaft 3'from the axle 4 of the vehicle. At appropriate times the worm 2 is lifted out of engagement with its cooperating gear 1 by means of the 'energization of the magnet 5. Energization of this magnet I is controlled by the apparatus in accordance to its initial clear position when it has been released from the worm 2. The contact 14 with track conditions as will be hereinafter more fully referred to.

The worm Wheel 1 has its initial position defined by means of a lug13 fixed upon it which comes against a spring "contact 14 which in turn comes against the stationary stop 15. A spring 16 secured at one end to the worm wheel and at the other to'a stationary part 17 tends to return'thegear 1 when released from the lug 13 comes into engagement with the contact 18 'so that when the gear 1 has left its initial (clear) Iposition these contacts will be closed, and when the gear is in its initial position these contacts will be opened, fora purpose as will be hereinafter referredto. Y r

The brake magnet 6 when deenergized causes the air brakes to be applied by per;-

mitting a valve in the air vent pipe 7 to open.

Normally this valve is held closed by the energization of the magnet 6 caused by the closing of the circuit of that magnet through the battery 8 and contacts 9 mounted upon but insulated from the worm wheel 1, connection between these contacts being made by a metal segment 10 fixed'upon but insu- F latedfrom the speed controldisk 11 which has circumferential ratchet teeth 12, the contacts '9 bearing upon the segment 10. The

speed control disk 11, which is rotatably mounted, tends to be turned inthe direction of the arrow 6, (the same direction as the arrow a) by imeans of a'spring' 19 having one end connected to'the stationary member '20 while the other end is connected with the piston 21 of a dash-pot which inturn is con nected by a band or cord 22 with the periph cry of the speed control disk 11. Thespced control 'dlsk has 1ts turn ng measured by lapse of time ratherthan by distance traveled as in the case of the worm gear disk 1, the rate at which the speed control disk 11 turns being'controlled regulating the dash-pot i'n'a well known manner'to allow the piston to move faster or slower under the'infiuence' of the spring 19, it being preferable that the dashpot shall be regulated to permit a relatively fast movement at the fore part of the downward movement or" the piston and then I slower, the speed curve of the piston preferably simulatingthe braking curve of the The speed control disk is normally vheld'in its initial -position,-that is, with its train.

stoplug 23 against the stationary stop 24, by

meansof; a dog 25 pivotedona stationary part and on an axis parallel to the face of,

V stationary stop 24: is another stationary stop 28 serving to define the initial caution position of the worm wheel 1 as will be here inafter more particularly referred to.

' .A magnet 29 is normally deenergized un- ,der clear conditionsbut is energized under V cautionfconditions; When the 1nagnet 29 is deenergized the sprmg 30 tends tomove the tall of a pivoted, bracket 31 against the limiting stationary stop 32, at'which time the'spring contact 33 mounted upon theother arm of the bracketiil isout of the path of thelug 13.- lVhen, however, cafitionPconditions exist the magnet attracts the; tail;

i V ed into the path of the lug 13 so that ofthe bracket 31 against the resistance of the spring so that it projects contact 33 into the path of the lug 13 but not quite touching the stop 28'. The result is that when the lug 13 has moved past the spring arm 33, and tending to bereset under caution conditions it will come against the arm 33 'which'will be forced against the stop 28 thereby preventing any further bilCnW'ftld movement of the worm wheel 1 and also separating the contact 33 from the contact 34, thereby opening the circuit between them for a purpose as will be hereinafter referred to. If. the wheel 1 is reset under clear conditions the member 33 will not be project} the Wheel will be returned to the initial clear position. r

The worm wheel 1 also has pivoted upon it a pawl 38 tending to be pressed into engagement with the ratchet teeth 12 on the speed control disk by a spring 36. This pawl has the detent point or nose and the tail 3?. The tail 3?, during the movement of the worm wheehengages the inner edge of the stationary segment 40 and so holds the nose 35 of the pawl out of engagement with the ratchet teeth 12 until it reaches the indented or cut away portion 41 a ter which the ratchet engages the teeth 12.

It will be observed that when the pawl is in engagement with the teeth the wormwheel 1 cannot move in the direction reverse to the arrows without carrying the speed control I disk with it, but on the other hand the worm wheel may move in the direction of its arrow independently of the speed control disk.

In order that the run-down and speed control devices as just referred to may be T caused to operate in conformity with cond tions of the track ahead, there are provided upon the vehicle two thermionic vacuum tubes, of the audion type, 42 and 43, each of which comprises a heated element, a grid and a plate as well understood and conventionally illustrated. The filament or heated element is in each case supplied with current from batteries 44 and'45 in the usual way and the desired control is effected by changes 1 in the value of the current in the plate cir V cuits according to whetherthe respective tube is in a condition of oscillation or non-oscillation. The oscillatory current is trans ferred from one tube to another by inductive action between the coils 92 and 93 located on the track, and the corresponding train. carried inductors.

lVith regard to the tube 42 there is in circuitbetwecn the plate 46 and the filament '47, a battery 48 and electro-inagnet 49 and a variable inductance 50. The grid 57 is connected through a conductor 51 with one-terminal '52 of the coil53, while the other terminal 54 of that coil is connected by a conductor 55 through a variable condenser 56 with the plate 46. The filament 47 is connected by a conductor -'58-with an intermediate tap 59 of the coil 53. Connected across the conductors 51 and55 is a variable condenser 60. The arrangement and construction is such that when the tube 42 is acting as an oscillator the plate current will be of sutficient strength to attract the armature of the relay 49 and when the tube is non-oscillating the plate-current'is reduced so that the armature will be dropped.

. It will be seen that the armature cooperating with the coil 49 is divided into two parts, one insulated from the other, one of which parts isadapted to engage with the back contact 80, while the other part is adapted to engagewith the forward contacts 81.and 82. Then, therefore, thearmature is dropped it establishes connectionsfrom one terminal of the battery 7 7 through the relay armature, contact 80, conductor 83, relay coil84 and conductor 85 to the other terminal of the battery 7 7 The coil 84 being thus energized attracts its armature 86.

The armature 86 being attracted, contacts with the forward contact 87 and thereby closes a circuit through the coil of the relay 88 across the terminals of the battery '77. The relay 88 then picks up its armature 89 and establishes aconnection with the forward contact 90 which is connected by the conductor 91 with the contact 82 of the relay 4.9. When the armature of relay 49 is lifted the contact 82 is connectedw ith the contact 8land thence circuitv is made through the magnet 29 and the magnet 5 to one side of the battery 77; the relay 84 having a holding cir cuit made through its armature and the con,-

tacts 33 and 34, holds its own circuit closed so long as the contacts 33 and 34 are in engagement and thus maintains the circuit of the magnet 88 which maintains the circuit through the magnet 5 which raises the-worm. 2 and disengages it from the worm wheel 1.

It will be seen that the circuit of relay 88 is initially established by the dropping of the armature of the relay 49 whereby the circuitof the coil of the stick relay 84 iscompleted, and this inturn establishesby its armature the circuit of thecoil 88. After the relay 49 picks up its armature again the circuit of the coil 84 will be maintained as above stated. Also, the energizing ofmagnet 49 will establish the circuit through magnets 29 and 5 permitting the worm wheel tobe reset. having been made by the energization oft-he The initial circuit of the coil 88 I magnet 84 upon the dropping of the armasothat these relays remain closed untilthe,

circuit'is opened at the contacts '33 and 34. The armature of the relay 49- having been again raised, the circuit through the magnets 29 and 5 across the battery 7 7 is made through the contacts of the relay 88 and contacts 81 and 82 of the relay 49, and obviously the circuit of these magnets 5 and 29 will be'broken when the magnets 84 and 88 are deenergized bytheuseparation of the contacts 33 and'34.

' Referring now to the vacuum tube 43, it Willbe seenthat'the grid 61 is connected by a conductor 62' with one terminal 63 of the coil 64. The plate circuit extends from the plate 65 through a variable reactance 66, one Winding 67 of the relay 68 and the battery 69 to the conductor 70 which is connected both withthe filament or heated element 71 and with an intermediate tap 72 of the coil 64. Also acircuit may be traced from the plate 65 through the variable condenser 73 and conductor 74 to the other terminal 75 of the coil 64. A variable condenser 76 is connected between the terminals 63 and 72. Then the tube43is not oscillating the armature of the relay 68 will not be picked up owing to the low value of the plate current. If, however,

' the tube 43 is oscillating the armature of relay 68 will be picked up owing to the increased value of theplate current and will then close the circuit from one terminal of run-down device moving slightly from its initial position; WVhen, however,the rundown device has been reset to its initial position the contacts 14 and18 will open, thereby permitting the armature to drop and it cannot be again raised until the tube 43 again becomes oscillatory by reason of certain track conditions as will be referred to later.

' Spaced along the trackway are a'series of trackinstruments each comprising two coils 92 and 93, two of the terminals of which are connected together by a: conductor 94 to which is connected aconductor including a variable'condenser 95.: The other terminals of the coils are connected respectivelywith the conductor 96 and the conductor 97 the latter connection includingthe variable condenser 98. r i

Referring particularly to Fig. 2 a railway comprising the lines ofrails 200, 201 and having the rails divided intoblocks by sections of insulation as 202, 202, and 203, 203.

and 204, 204 has/moving along it a vehicle 'be of the semaphore type indicated by the pivoted semaphore arms 206, 207 and 208, which semaphores are precisely the same and may be operated from the track blocks to indicate conditions of certain portions of the track. Thus the signal 208 indicates the conditions in the block f, the semaphore 207 indicates conditions in the block 6 and the semaphore 206 indicates conditions in the block (7. Located in thetrackway at the end of the block 0 and adj acent'the beginning of block d are the two coils 92 and 93 referred to in connection with Fig. 1 as adapted to cooperate with the coils 53 and 64 upon the vehicle. i

As will be seen, the'conductor 97 is connected with a contact 209, the condenser 95 is connected with a'contact 210 and the'conductor 96 is connected with a contact 211. The contacts 209, 210 and 211 are adapted to be engaged by the semaphore arm so that the semaphore arm as it turns upon its pivot will at one time connect the contact 209 with the contact 211 (as inth'e position shown at 0) and atanother time connect the contact 210 with the contact 211, opening the circuit between the contacts 209 and 211, and at another time will rest uponthe unconnected contactssame in construction as the signal 206 and that the contacts and connections are the same 111 arrangement in each case.

Regarding the coils 92b and 93b and the semaphore signal 208, however, it will be seen that :there is a vehicle or train in the block ahead and consequently the semaphore arm is in danger position and the circuits of both of thecoils 92b and 936 are open. The semaphore arrn'207 at the end of block (Z and the beginning of block 6 is in caution position, and it will be seen that the circuit of the coil 93a is open, While the circuit of the coil 92a is closed through the condenser 95a (which is exactly the same in construction as the condenser 95). It will further be seen that in the apparatus at the end of block 0 and beginning of block 0? the semaphore is in clear position and the coils 92 and 93 have their circuit closed inseries through the condenser 98. j 2

The operation of the apparatus may now be traced as follows. l i V The apparatus having assumed a clear condition at the beginning of block 0 theparts upon the vehicle will be in condition as shown in Fig. 1, the tube'42 being normally oscillating and the-tube 43 being normally non-oscillating. As the vehicle proceeds along the track thedriving gear will drive the worm wheel 1 in the direction of the arrow a and almost simultaneously with the beginning'of this driving the contlacts 14 and 18 will be closed; The circuit of brake magnet 6 will be closed throughthe contacts 9 and 10 and the brakes will be held off. The vehicle thus proceeding, the nose 35 of the dog 38 will beheld out of engagement with the ratchetteeth' 12 by the stationary seg-- ment 4() (and the speed disk 11 is held stationary by the dog 25 1,

It will be observed"thatthelsegment 10 upon the speed control-diskis of considerable extent so that the worm wheel 1 carrying the contacts 9 may have considerable range of movement without causing the contacts 9 to slide off of the segment 10. Just before i the tail 37 of the dog reaches the depression 41, and just before the cam end of'the seg ment 26 enters beneath the tail of the dog 25 to removeits nose'from the ratchet teeth, and just before the lug'23 leavesthefstop 24, the coils 53 and 64 on the vehicle'run'over' the coils 92 and 93 which, as we have seen, are set for clear conditions in" the block ahead ((Z), and the adjustments and constants of the connected circuits in the track and on the vehicle are such that not only is the tube ,42 maintainedoscillatory but'the tube 43 has its character changed from non- 1 oscillatory to oscillatory. When the tube 43 becomes oscillatory the armature of the relay 68 is picked up, and is held up a'circuit through the contacts 14 and 18 and the reset magnet 5 and winding 7 8., The reset magnet being energized the worm 2: is then drawn away from its wheel which is returned to its normal position by the spring" 16, with its lug resting against the contact 14'and stop 15. During all of the movement i thus far described, both forwardand return,

of the worm wheel the dog-nose :35 has been held out of engagement with the ratchet teeth 12' and the speed control disk .11, has been held stationary by the dog or pawl25 so that no movement of the speed controldisk v has takenplace. It will also be observed that in assuming its initial position the worm wheel 1 has opened the contacts 14 and 18, thereby deenergizing the relay 68 and permitting its armature to fall, so that the apparatus is in the same condition at the be ginningvof block d as it was in blockc. 7

The vehicle then proceeding along block all have itscircuit closed through the condenser.

95a. The coil 93a not having its circuit closed, there will be not reflection of the wave 1n the coil 53 to the coil 64' so that the coil 64 will remain non-oscillating. Connections of the circuit of the coil 920;, however, are such that-the tuning and oscillatory character of the circuit of the tube 42will be destroyed so that the tube 42 will become non-oscillatory. The armature, therefore of the-magnet 49 will be dropped closing the initial circuit at the contact for the coil 84 which will cause the armature 86 to lift and close the circuit of the coil 88 whereupon the circuit is made through the contacts 89 and 90, 81 and82 and the armature 29 and the mag net 5. The magnets 5 and 29 are thus energized and this takes place after the lug 13 haspassed the arm 33. The energization of the magnet 29 causes the armature 33 to be thrust into the path of the lug 13 and the energization of the magnet 5 causes the worm wheel'l to be released from its worm so that Wheel 1 will be returned by its spring 16 to a position against the arm 33 and stop 28, namely the initial caution position as distinguished from the initial clear; position which exists when the lugv13 is against the:

arm 14 and stop 15, At the time this action takes place the dog having the nose 35 will have come into engagement withthe ratchet teeth 12 and the holding dog 25 will have been released from its ratchet teeth so that when the lug13 is against the stop 28' the speed disk 11 will have been reset sothat its 11g 23 isagainst the stop 24. It will be ob served thatthe pawl 38 permits the speed disk 11 to rotate clockwise under the infiu enceof spring 16, in being restored to the position illustrated in Fig. 1;

so I

When the lug 13 comes againstthe spring 1 contact arm 33 it will "separate the contacts 33 and 34 thereby breaking the circuit of the relay 84 which will result in the deenergization of the relay 88 and of the reset magnet 5 whereupon the worm 2 will again fall into mesh with the worm wheel 1. This being the condition at the beginning of the block a, movement of the train along the block will a cause theworm wheel 1 toturn and beginning with its initial vcaution position and the speed control disk 11 will move from its I initial position with the lug 23 against the stop ,24 under the influence of the spring 19 regulated by means, of the dash-pot 21. The speed control disk'll will move at a predeter mined rate, and the rate and the speed of the train will be limited because the engineer will'be obliged to so limit the speed'of his train that the. contacts 9 willInot be driven out of engagement with the contact segment 10 before the end ofthe block. If these con-.

tacts separate froni the segment 10 the ciritedin his speed within the block 8 so that upon, encountering a danger signalfor the next blockhis speed will not beso great that he will be unable to comply with the signal, It will be apparent, however, that in blocksof sufiicient length it is only necessary that hisspeed be limited for a distance at the end of the block equal to the braking distance of the train, and previous to this braking-distance a higher speed would do no harm. Forthis reason the jdash pot 21 is constructed (1n a manner .as is well understood in the art) so that for a time prior to the necessarybrakgazing time the dash-potwill .permit a fast movement ofits piston and so a relatively fast movement of the speed control disk 11, so that duringthe first part of the caution block the speed control disk 11 may move at 25 a relatively high speed and so permita rela-'- tively high speed of the vehicle Without dan-- ger of breaking the circuit of the magnet 6. At a time, however, to permit suiiicient braking distance at the end ofthe block in case of a danger signal .for' the blockahead, the

dash-pot 21 is so constructedthat its piston slows up and this speed of the dash-pot pis-l' ton may desirably be made .tosimulate the braking curve of the trainee that theengii neeris limited in his speed according to that 7 curve. Thispermission of higher speed at the beginning of a caution? block also has the function of permitting the use of the system on blocks of variable lengths. If, for in- 40 stance, the distance between-signals should not be of the normal length provided for in the apparatus as above describedthe train would run intoa section having the caution conditions but, the relatively high speed 451 would be permitted during the first part of the block inlwhich these conditions ex ist as just explained. The high speed of clear? conditionscould be maintained and then the apparatus would be reset to initial caution V or initial clear according to the COIIClltlOIl ofthe block ahead when the track coils for controlling the train for I that block are reached Of course, ifthereshou'ld be danger set for the block ahead the brakes would be applied'and the train stopped as will be hereinafter described. V p The train or vehicle continuing along the block *6 after the caution signal at thebeginning-of that block as shown in Fig. 2 and j above referred to, the vehicle coils 5.3 and 54 will, hear the end of the block, comeinto' cooperative relation with the track coils 92b and 93ba Since,ihowev er, the semaphore 208 v is inalfdanger position, the circuitsof both- "these track coilswillbe open so that they-will either of the vacuum tubes on the vehicle. No

change in the vehicle apparatus will therefore i I p be produced. so that as the vehicle enters the 1 f cuit of the brake magnet 6 will be broken and the brakes applied. The engineer is thus limblockf thejworm wheel 1' will continue its movement 'and unless the tram is sooner stopped by the engineer, the speed control diskll will reach thelimit'of its movement 1,

reduced rate of speed. 7 This is controlled by thespeed of dashpot 21 and the length of the contact 10. The'upper end of contact 10' is sufiiciently-long to permit'the train to stop just inside the caution block and remain there the full time required for stop 23 to contact with stop 27' without opening brake magnet circuit6. j If the signalat 208 were another caution instead-10f danger, the vehicle apparatus would be resettof-initial cai1tionand. proceed accordingly into block f. If the signal were iclear the apparatus would be reset to initial clear? and the vehicle would proceed along the block 7 accordingly. I

:Referring now to Fig. 3 of the drawings, there is therein shown equipment whereby the progress of a vehicle is automatically controlled in accordance with the conditions of the trackahead by controlling the thermionic vacuum tubes, it being possible, however, for

theengineer toobviate the automatic control by taking suitable action.

The vehicle equipment comprises two normally oscillating thermionic vacuum tubes of the audion type 100 and 101, and a coil 102 operatively related to the vacuum tubes so as to aflect the? magnet 103 for controlling the air brakes, together with suitable relays and other devices to effect the operation as indicated and as will be presently described more in detail. There is. also upon the vehicle a resetting or restoring device 104 which may be manipulated by the engineer to avoid auto-.

matic operation' of the brakes. Mountedin the track or along the right of way and ad:

jacentthe beginning of each block so'that it.

may cooperate with the vehicle coil 102 as it passes,'is a'coil105 having circuits adapted to be controlled by track conditions as will be hereinafter referred to. I

Theapparatus shown on the vehicle depends for its operation upon the change in plate current effected by change in the oscillatory'character of the vacuum tubes. The vacuum tube 100. has the usual heated element or filament 106, the grid 107, and the plate 108. Thefilament 106 is heated inthe usual way by meansof a-battery 109. The grid is connected'through a variable condenser 110 with one terminal of the coil 102 and also through a variable reactance 111 withthe other terminal of the coil 102.

The plate circuit extendsfrom the filament through the battery 112,the coil of the relay 113 and the variable reactance 111 to the plate 108. Also there is connected between the filament and plate the variable condenser 115 and the inductance coil 11 6 which is in inductive relation to the coil 111. This'tube being normally oscillating the plate current will normally be sufiicient to maintain the armature of the relay 113 lifted.

Similarly the tube 101 has the filament 117, energized in the usual way by the battery 118, the grid 119 and the plate 120.; The grid is connected through a variable condenser 121 with one terminal of the coil 102 anc through the variable reactance 122 with the other terminal of the coil 102. The plate circuit er: tends from the filament through the. battery 123, the coil of the relay 124 and the variable reactance 125 to the plate 120. Also there is connected in series between the plate and the filament a reactance 126 and a variable condenser 127, the reactance 126 being in in ductive relation to the reactance 122. The

circuits upon the car as just described are so tuned or adjusted that both tubes are normally oscillating, that is, when he vehicle coil 102 is not over or in cooperative relationshipwith the track coil 105. Normally, therefore, the currents in the coils of the relays 113 and 1241 are sufficient to maintain their armatures raised so that the circuit including the magnet 103 and the battery 128 in series is maintained closed while the circuit including the battery 128' and the caution signal light 129 is open. The brake magnet 103 is therefore normally energized and maintains the valve in the brake pipe closed so that the brakes are held oil. When, however, the train is passing a tIflCklHStIUIllG-Ilt or an in strument located on the right of'wayso that the train coil 102 is brought into cooperative relation with the coil 105, the oscillatory character of the vacuum tubes is changed accord ing to the circuit connections of the coil 105 which connectionsare controlled in response to the conditions of the track ahead, for instance by the operation of a way side signal;

The vehicle, it will be understood, is traveling upon a track divided into blocks in the" usual way and having'a coil 105 located ad jacent the beginning of each block as-shown in Fig. 2. It is also to be understood that there is at the beginning of each block a wayside signal of the semaphore tyne (also as shown in Fig. 2). Such a signal is indicated at 150 in Fig. 3. The arm of this signal is adapted in the clear position to close the contacts 128 and 129, when in caution position to close circuit between the'contacts'1290 and 130 and to leave the contacts 128, 129and 130 disconnected when the way-side signal is in the danger position. The devices 131 cillating as before stated, and the brakes consequently held off because of the energization of the track magnet 103, if the coil 102 comes into cooperative relation with thecoil 105 when the way-signal controlling it isin clear positionthe coil 105 will be short circuited and the efiect on the vehicle circuits will besuch that-the oscillatory character of the tubes will be maintained, the brakes will be maintained 0E and the train may proceed as usual.

If, however, the signal is at caution the contacts 129 and 130 will be closed so that the condensers 131 and 132 will be connected in parallel across the fterminalsrof the coil 105 so that by their efiect upon the coil 102 the vacuum tube 100 will become non-oscillating'while the constants in relation to thetube 101 are such that the last mentioned tube con- -The non-oscillation condition will continue only for the brief interval that the'coil 102 is passing over the coil 105 and for that'reascn the relay 113 is caused to be so slow in picking up its armature that the action of the signal 129 (which may be a lamp, bell, gong or other suitable device) will become efiective' to not fy the engineer. The retarding means for causing the armature to be slow in rising may be dashpot or Incansfor preventing rapid building up of current in the coil 113 or other well known and suitable means.

If the signal 150 is at danger, it will close no circuits and thecircuit of the track coil 105 will remain closed through the condenser only. When the vehicle coil 102 is in cooperative relation with the track coil 105 under such conditions the tube 101 is rendered non-oscillating whereupon itslplate current diminishes to such an extent that the'relay 121drops its armature thereby breaking the circuit of anddeenergizing the brake magnet With the tubes on the vehicle normally osheld off. By this means the engineer ma 103 and the brakes will beapplied. The engineer is advised in advance of this condition by the caution signal 129 and also by c servati'on otthe wayside signal, and'may avoid the application of the'brakes-by manipulating the device 104so asto close the norm'allyopen c nnection between the conductors 123 and 124. This places a shunt about the contacts of relay 124 so that the opening thereof does not open the circuit through the battery and brake magnet, the magnet remains energized and the brakes are avoid the automatic action under a danger condition but insuresthat he must be cognizant of this condition in taking manual action to avoid automatic action to allow the train to proceed'and any inattention, resul ing in failure to avoidthe action, will causeautomatic application of the brakes.

-Re;terringto Fig. 4 thereis therein shown I a vehicle equipment whereby the application or withholding of the application of ti e brakes or the vehicle 18 controlled by. the controlling of the oscillation of a thermionic'vacuum tube of the audiontype. Inthis apparatus a single vacuum tube is shown which is adapted to indicate clear and danger conditions, the latter of which may be modified in itsoperationupon the brakes by means ofmanipulative action of the engineer. The

I track coil, instead of being controlled by a The track coil 144 hasconnected across its semaphore as i the preceding illustrations n connection with Figs. 1, 2 and 3, is con trolled directly by the usual track relay which as is well known reconnected across the track rails across which abattery is connected so that the relay is normally energized but when a train stands on the rails the relay is short circuited and deenergiaed. The train carried apparatus comprises the thermionic vacuum tube 133'having the heat- 7 ed element or filament 134, the'grid-135 and the plate 136. The filament is heated in the usual wayby a battery 137; The grid135 is connected with one terminal of. the vehicle coil 138. Through theplate 136 a'circuit ex tends from the variable reactance 140,

through the coil of the relay 141 and the bat tery 142to an intermediate point of the vehicle coil 138. Also a connection extends from the reactance through the variable condenser 143 to the other terminal of the coil 138. 11 condenser 139 is connected between the plate and grid circuits as shown.

141 willbe sufficient to maintain the armature raised and the circuit of the brake magnet 147 closed in series with the battery 148 so that the brakes will be held oil. If the coil 138 comes into cooperative relation with the track coil 144, if the condition of the track ahead issuch Cclear condition) that the armature of the coil-146 is lifted, the condens er is short circuited and also the circuit of the coil144 is closed by-the short circuit.

The tuning of the circuits related to the vacuum tube on the vehicle isjnot changedand the relay-141 maintains its armature lifted and the brakes are held otiso that the train can proceed as usual. If, however, when the coil 135 is in cooperative relation with the coil 144, there are danger conditions in the.

uponthebrake controlling magnet 147 will be deenergizedxpermiteing the brake valve to open, whereupon the brakes will be applied. The engineer or operator may, however, .avoid the applicationof the brakes by closing abnormally open circuit at the hand operated switch 149 which will operate to close a short circuit about the armature contacts of the relay 141'so that when the relay 141drops its armature the circuit of the .brake magnet will stillbe maintained andthe application of the brakes will be prevented.

The engineer is thus able by taking action,

to prevent the application of the brakes and upon his failure to do so thebrakes will be applied under the conditions as indicated. a

ReferringtoFigs. 5 and 6, the vehicle equipment comprises a normally oscillating thermionic vacuum tube 300 having the heatedelement or filament 301 energized by the usual battery 302, thegrid 303 and the plate 304. The vehicle equipment also comprises a normally non-oscillating thermionic vacuum tube 305 having a filament'306 energized by the usual battery 307,a grid 308jand a plate 309.- Circuit is' made from the. plate 304 through the variable reactance 310, the

coil ofthe relay 311 and the battery 312'to the filament 301. Also connection is 'made from the plate 304 through the variable condenser'313 and the conductor 314 to one ter-- minal of the coil 315. The grid 303 is connected'by a conductor 316 with the other terminal of the coil while the filament 301 is connected by the conductor 317 with an intermediate tap of the coil 315. A variablefcon denser 318 is connected between the conduce tors 314 and 316 connected to the terminals of the coil 315.

The-tube 305 has its plate 309 connected through a variablereactance 319, the coil of the relay 320 and a battery 321 to the filament 306. The plate 309 is alsoconnected through a variable condenser .322and a conductor 323 with one terminal of the coil 324 and the filament 306 is connected by a conductor 325 with an intermediatetap of said coil. A variable condenser 327 is connected between the con-- ductors and 326. The tube 300 being normally oscillating, the current in its plate cir cuit through the coil of the relay 311 will normally be suifieient to maintain its arma ture lifted as shown. On the other hand, the

tube 305 being normally non-oscillating, current in its plate circuit through the coil of the relay 320 will normally be insufficient to maintain its armature raised so that it will track magnets and vehicle coil as the vehiclepasses along the right of way Wlll cause a" single cycle of electro-motive force to be induced in'the circuit of the coil 328. Onehalf of said cycle is opposed to the electromotive force of the battery 331 so that it tends to cut down the current flowing in 'the coils of the relays 329 and 330. If this cutting down of current is suihcient the armatures of either or both of the relays 329 and 330 will be dropped. Theparts are so proportioned and arranged that the armature of the relay 330 will drop at any speed of the vehicle above miles an hour and the armature of the relay 329 will also be dropped at vehicle speed above 10'miles an hour. Normally the armatures of the two relays 329 and 330 in series close the circuit of the coil of the relay 332 through the battery 333 so that the coil of the relay 332is normally energized. It therefore normally holds its armature lifted and thereby closes the circuit of the brake ma et 334 through the battery 335 and this bra e magnet being normallyenergized' maintains the brake valve closed so that the brakes on the vehicle are held off. The brake magnet 334 is made 1 sluggish in its operation bycausing a short circuited coil to be inductively related to its battery energized winding or in other suitable ways. It will thus-be seen that when either or both of the relays 329 and 330 drop their. armature or armatures, the brake magnet will be deenergized and the brakes applied.

Whenever the current in the plate circuit of the tube 300 through the magnet of the relay 311, by reason of change in the oscillatory character of the tube, becomes so small that the armature of the relay is no longer sustained, the armature will drop and close a circuit through the coil of the relay .336 and V the battery 337. The relay 336 will then pick up its armature which will'close circuit. rom the battery 337 through the winding of the relay 338. The armature ofthe re lay 336 also closes the circuit of its own winding, through the armature of the relay 3'38 and across the battery 337 independently of the armature of the relay 311. The efiect of the tube 300 causing its plate cur rent to be reduced and the armature of the relay 311 to be dropped, is only momentary sothat after a very short interval that armature is picked up again. The relay'338 is sluggish in picking up by reason of having a short circuited winding in proximityv to its battery connected winding'o'r said re lay maybe made sluggish in any of the other suitable and well knownways known tothe art.: When therefore themore quickly acting I V relay 311 has picked up its armature, butthe more sluggish relay 338 has not picked up its'armature, circuit through one of the windings of the relay 339 and the battery 337 will be completed through'the armatures'of the relays 336,338 and 311. Whenisufficient time has elapsed for the relay 338 topick up its armature, the circuit through the winding of the relay 336 and the winding of the relay 339as just referred to, will be broken and also the circuit of the winding of the relay 338 will be broken. 7

When the oscillatory character ofthe tube 305 is so changed from normal to cause a suflicient increase in its plate current through therelay 320 to cause the relay armature to be picked up, circuit will be closed through the coil of the relay 340 and the battery 341.

The relay 340 being thus energized will pick 7 up its armature. This will cause the circuit of the stick relay 340 to be made through'its own armature and the armature of the relay 342, battery 341, magnet 340 and left contact of relay 340 independently of the contacts to the relay 320. The relay 342 is made sluggish in operation as has been described in connection with relay 338. The armature of therelay 340 will therefore remain stationary after the 'momentary operation of the relay 320 and for a period as determined by the sluggish operation of the relay 342.

The lifted armature Ofthe relay 340 also closes the circuit of the coil of the relay 342 in series with its own armature and themmature of the relay 340 across the battery 341.

Also with the armature of the relay 349 liftedand that of the relay'342 not yet raised on account of the sluggish action of the relay, circuit will be made through another winding on the relay 339 acrossthe battery 341 by means of the conductors 343 and 344 circuit being made at this time across'the bat tery 341 through the'winding of the-relay 345 by means of theconductors 344 and 346.

The two windings of the relay 339 are cumulative so that when either or both are energized as described the armature of the relay Will belifted.

Referring to Fig. 6, there is there show I a railway track divided into blocks 9, h, z and is, track coils 347 and 348, 347a and 348a and 347 b and 348b arranged in pairs at the beginning of each block, a vehicle or train 340 and semaphore signals 351, 352 and 353 1 all as described in connection with Fig. 2.

Fig. 6 has however in addition a permanent magnet in the track, one following each pair of coils at the beginning of each block as for instance the permanent magnets 349, 351 and The operation of the apparatus'may now beindicated as follows: if the train is procoils will be connected in series through the .net 349 when that coil later comes into -induc.-'

variable condenser 353 whereby, the" tuning and constants being suitable .asis well understoodinthe art, the tube 305 willhave. its

oscillatory condition changed so that its plate;

current through the relay 320 "will cause that relay to pick upand the sluggish relay 342 Will cause'the conditionpestablished to 'persistfor an appreciable length of time The tube 300 stillretaining' its oscillatory condition so that its relay 311 retains its armature, the windings of the relays 339 and 345 will be energized from the battery 34]:

only, (not from 337). The 'armature's of both these relays will therefore be lifted and me-' chanically hold, the armature of the relays 329 and 330 in closed position so that the brakes are'held off and the train may proceed as usual regardless of any impulse which may be induced in the'coil 328 by the track magtive relation to thatmagnet,

-The train new proceeding under'fclear? conditions along the block h, adjacent the end of that block the vehicle coils 315 and 324' itmay have other embodiments without de-' will come into cooperative relation respectivelyr withv the track coils 347a and 348a.

Here however, the signal 351 is setto indicate] caution conditionsin the block ahead, and

causes the circuit of coil 348a'to be open and the circuit of the coil 347a-to be closed through the variable condenser 354. Theconstants' and tuning are then such that the oscillatory character of the'tube 305: is not net 351,at a speed as greatas' 30 miles an; hour (the speed at which the coil will have induced. in it an impulse suflicient to reduce the current-in the relay 330 to or below the dropping point of its armature) the armature of relay 330 will break the circuit to the brake magnet and application of the brakes will ensue. If the speed'is kept within the. limit 7 the train'may proceed l I g The train new proceeding under Vcaution conditions along the block z',the. coils 315 and; 324 will, near the end of the block,,come:respectively into cooperative relation with the track coils 347 b and. 348b. The semaphore here is set to danger and the circuits of' both the coils'347b and 348?) are suchthat as the vehicle passes no, change will becaused in the oscillatory.- character of either of the, vacuum tubes, Neitherof the armatures of the relays 339 nor 345" will belifted and neither -ofthe armatures ofthe relays 329 and 330 will"be lockedand if-the train-runs into the dangerlblockso thatthevehicle 'coil 328 passes the. permanent magnet at a speed greater than ten miles per rhour (the limit of speed without dropping the arma-- ture ofrelay 329): the; circuit of' the brake magnet will be openedfand the brakes ap-' plied; The brake magnet is made slow actingior sluggish asabove'referred to so that if the vehicle should be running .in the opposite direction v-fromthat indicated, the brakes would not'be applied :by reason of the impulse received 'from'the' permanent magnet in the track. Also such actioncould be prevented by passing over properly energized coils acting upon the vacuum tubes. In'this way the vacuum-tubes can exercise their control of thettrain even though it may be moving in the. direction the reverse of that indicatedin the drawings.

lVhile the invention has been illustrated in whatare considereditsbest applications,.

parting from its spirit and is not therefore limitedto ing's.

- Whatwe claimis'zw' 1. The combination with a vehicle adapted to travel 'along'arightofway, of means on' saidivehicle for affecting'the progress there-. of, means biasedfby theprogress of said ve hicle to affect the. aforesaid means, means including a thermionicyacuum tube becoming an oscillator under suitable circuit conditions for controlling said biased. means, and'aninstrument 'on-said right of way and connections on said vehicleadaptedto com the structures shown the d'raw- V trol the character of said tube and thereby control said biased means.

2. The combination with a vehicle adapted to travel along a right of way, of means on said vehicle for affecting the progress thereof, means biased by the progress of said vehicle to affect the aforesaid means, means including a thermionic vacuum tube becoming an oscillator under suitable circuit conditions for controlling said biased means and an instrument and connections on said vehicle adapted to control the oscillatory character of said tube to thereby control said biased means.

3. The combination'with a vehicle adapted to travel along a right of way, of means on said vehicle for affecting the progress thereof, means biased by the progress of said vehicle to affect the aforesaid means, means including a thermionic vacuum tube becoming an oscillator under suitable circuit co nditions for controlling said biased means and an instrument controlled by conditions of. the right of wa ahead and connections on said vehicle adapted to control the character of said tube to thereby control said biased means.

4. The combination with a vehicle adapted to travel along a right of way, of means on said vehicle for affecting the progress thereof, means biased by the progress of said vehicle to affect the aforesaid means, means including a thermionic vacuum tube becoming an oscillator under suitable circuit conditions for controlling said biased means, an instrument controlled by conditions of the right of way ahead and connections on said vehicle adapted to control the oscillatory character of said tube to thereby control said biased means.

5. The combination with a vehicle adapted to travel along a. right of way, of means on said vehicle for affecting the progress thereof, means biased by the progress of the vehicle to affect the aforesaid means, speed control means cooperating with said biased means, means including a thermionic vacuum tube becoming an oscillator under suitable circuit conditions for controlling said biased means, an instrument on said right of way and connections on said vehicle adapted to control the character of saidtube and thereby control said biased means.

6. The combination with a vehicle adapted to travel along a right of way, of means on said vehicle for affecting the progress thereof, meansbiased by the progress of the vehicle to affect the aforesaid means, controlling means involving time as an element cooperating with said biased means, means including a thermionic vacuum tube becoming an oscillator under suitable circuit conditions for controlling said biased means, an instrument on said rlght of way and connections on said vehicle adapted to control the character of said tube and thereby control said biased means. 1

7. The combination with a vehicle adapted to travel along a right of way, of means on said vehicle for affecting the progress thereof,

means controlled by the distance traversed by said vehicle along the right of way, an actuator therefor, a disconnecting device for said actuator, means for restoring the con-' trolled means, a plurality of vacuum tubes, one of which governs the extent to which sa1d restoring means shall act efiecting operat1on of the disconnecting device, another of said tubes controlling the first tube as to its effecting the operation of the disconnecting device.

8. The combination with a vehicle adapted to travel along a right of way, of means on said vehicle for affecting the progress thereof,

means controlled by the distance traversed by said vehicle along the right of way, time controlled means associated therewith and governed thereby, an actuator therefor, a disconnecting device for said actuator, means by said vehicle along the right of Way, time controlled means associated therewith and governed thereby, an actuator therefor, a disconnecting device for said actuator, means for restoring the controlled means, a plurality of vacuum tubes, one of which governs the extent to which said restoring means shall act and effecting operation of the disconnecting device, another of said tubes controlling the first tube as to its efiecting the operation of the disconnecting device, said restoring means being effective upon disconnection of said actuator therefrom to reset the time controlled means during part of its movement and the first mentioned vacuum tube acting when the normal condition of the tube is disturbed to prevent the restoringof the distance controlled means beyond a point Where the time controlled means is not reset by further movement of the distance controlled means;

In testimony whereof we have signed this specification this 18th day of January, 1928.

THOMAS W. VARLEY. WILLIAM C. NEIN. 

